<!doctype html>

<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0,
                            maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>计算器示例</title>
</head>
<body>
<form action="/add">
<!--  action="/add" 要和 action="/add" 一样  -->
    <div style="margin-top: 100px; text-align: center">
        <h1>计算器</h1>
        数字1: <input name="num1" type="text"><br>
        数字2: <input name="num2" type="text"><br>
        <input type="submit" value=" 提交 ">
    </div>
</form>
</body>
</html>

